In this, the first of our articles examining the jargon of a standard personal computer, we take a look at the Processor, or Central Processing Unit (CPU); We explain what Mhz and Ghz are measuring and why it?s important in comparing one processor with another, and we look at what the differences are between the various manufacturers.

Firstly, what does a processor actually do?

Well, put simply, the processor is the brain of the computer ? but more specifically, the part of the brain that does the work ? not the part responsible for storage of information, that job belongs to another component which we will cover later; Not even the part for storing items of information that are about to be worked on, or have recently been worked on, that too, is the responsibility of another component. The processor is the real power-house of the computer ? every activity, event, instruction, item of information, will pass through the processor for action at some point, and then, once the work has been completed, be handed off to another component with appropriate instructions.

Next we need to consider how this work is carried out by the processor. If you consider that a large piece of work you were going to do at your house, say, decorating a room, is actually a number of smaller items of work pieced together (taking down pictures; moving furniture; buying paint; etc), then you can begin to see how a computer processor deals with a large job, by breaking it down into smaller activities. More specifically, if a computer processor were to take charge of decorating your house, the processor would dissect each activity into smaller activities of precisely the same length of time ? even if that meant that certain of these items would not be completed in one ?stretch? of time, and need to be split over several ?stretches?. Thus a processor only allows an item of work to be ?in progress? for a specific length of time, before that activity must give way to another, waiting in-line. This length of time is called a ?cycle?. We measure a processor?s performance in cycles per second, and one cycle per second, in a number of disciplines, not only computing, is called one hertz; one thousand cycles per second is called one kilohertz (KHz); One million hertz is called one megahertz (MHz); and one billion hertz is called one gigahertz (GHz); Thus a 2.6 GHz processor can actually perform 2.6 billion processor cycles per second.

The final item we need to consider is the processor architecture. We don?t need to understand the precise physical nature of each different processor architecture, but we do need to understand that though we measure each processor using the same measurement (MHz and GHz ? cycles per second), we are comparing different constructions so this measure alone, is not the only one to make when comparing processors.

Consider that a competition between two similar sized motor engines, manufactured by very different companies, would produce different performance results, despite their size being equivalent. Comparing computer processors purely using their speed, without taking their architecture into consideration, would yield similar performance differences.

Like with motor vehicles, which have a manufacturer and a model, processors have a manufacturer and an architecture, thus an Intel Pentium Processor, is manufactured by Intel, and its model, is Pentium; An AMD Athlon, is manufactured by AMD, and so on. With processor architecture one thing is instantly clear: The more mature, stable and superior the architecture, the greater the cost.

Additionally, we need to be aware of architecture revision, thus an Intel Pentium 3 1.5GHz processor, would have a poorer performance than an Intel Pentium 4 1.5GHz processor ? same architecture, different revisions.

Processors are just one of many elements that you need to consider when comparing two or more computers. Nevertheless, they are important elements, and hopefully you now have an understanding of what you?re comparing.

In two weeks time I will continue our foray into the components of a personal computer, with a look at computer memory: What it is, how it?s measured, what to be aware of.

@EDITRULE:

Bob Mellor is a senior business technologist with nearly two decades experience. He is a Professional Member of the British Computer Society, and currently Technical Services Manager at Bermuda Microsystems Group. He can be contacted on bobbmg.bm